Projectile



May 20, 1924. 1,494,718

- J. B. SEMPLE INVENTOR Patented May 2%, 1924.

PATENT OFFICE.

JOHN B. SEIVIPLE, 0F SEWICKLEY, PENNSYLVANIA.

PRO J'ECTILE.

Application filed August 8,1922. Serial No. 580,478.

the particular conditions attendant upon the use of armor-piercingprojectiles in mind,

and my immediate object, has been to overcome difficulties encounteredin attempting to build a delay-action armor-piercing shell.

My invention may, for example, be embodied in the projectile structureillustrated in the accompanying drawings. Fig. I is a view in axialsection of the complete projectile structure. Fig. II is a similar viewto larger scale of the fuse alone. Here again, in the particularconstruction of the fuse, the showing is exemplary.

The problem of building a delay-action fuse for an armor-piercing shellis different from and much more diificult than the problem of buildingan ordinary fuse, be-

cause the progressive functioning of the fuse must continue through thedesired interval of time and space, after the structure has sustainedthe tremendous shock of impact upon armor plate. The stress then exertedupon the fuse, tending to drive it forward, may be stated in generalapproximation to be one hundred thousand times the weight of the movablepart of the fuse.

It hitherto has been impracticable, under the limitations of dimensionimposed by service, to build a delay-action base fuse which under thetremendous strainindicated, will not immediately be either torn asunderor so stretched or distorted as to fail to function.

My invention is found in mounting the fuse, not in a screw-threadedorifice, opening from the outside through the wall of the shell (eitherat the base or at the point) into the cavity which contains the burstercharge, but in placing the fuse within the burster-charge cavity, at theanterior end thereof, and with such' adaptations of form and structureas I shall presently describe. Referring to the drawings, the shellitself is indicated at 1, Fig. I. l/Vithin it is formed the cavity 2 forthe burster charge. 3 is the base plug closing the burster charge cavityto the rear. Within the cavity 2 are found the burster charge 4 and thefuse 5. The fuse is, as has already been said, illustrated in detail inFig. II, and description of it will presently be given.

Fig. I may be taken to show diagrammatically, and without elaboration ofdetail unnecessary to a comprehension of this invention, anarmor-piercing projectile. The body of the shell is formed as anintegral block of metal. The cavity for the burster charge is axiallyarranged within the body of the shell, is circular in cross section,opens rearwardly, is closed forwardly, and tapers forwardly, in generalapproximation to the external shape of the shell. The thickness of thecavity wall diminshes from the forward end rearwardly; the mass of metalis so disposed as to be strongest in resistance to longitudinal stress.These general features are now standardized.

I take advantage of the shape of the interior cavity, to accomplish moreeffectively the ends I have in view. I make my fuse with exteriorcontour to conform closely in size and shape, so that it may fit snuglywithin and abut firmly upon the wall at the forward end of the cavity,and I preferably shape the fuse rearwardly with a fiat face which whenthe fuse is brought to position, as shown in Fig. I, extendsperpendicularly to the axis of the shell. I I This position of the fuse,at the forward end of the burster-charge cavity, is the position towhich a base fuse, torn from the base plug on impact upon heavy armor,tends to move; the shape is that which any fuse placed in the forwardend of the cavity, would on impact tend to assume. The tapered anteriorsurface of the fuse is, under stress of impact, supported at every pointupon the correspondingly tapered cavity wall. Such is the preferredconstruction; but manifestly the invention would be realized, eventhough this correspondence in shape, of fuse to cavity wall, were notcomplete, so long as the areas of contact were sufficient to sustain thethrust.

The fuse having the general shape indicated may be held within thecavity 2 in the position shown in various ways. For instance, it maybesecured by screw-threaded engagement with the cavity wall. This is theusual way of securing a fuse in the body of a shell, and such being thecase, I have deemed it unnecessary to make particular showing thereof. Iprefer, however, to secure the fuse in place in the manner illustratedin Fig. I; the body 4 of the burster charge, filling the otherwiseunoccupied portion of the cavity and held in place rearwardly by thebase plug 3, itself furnishes adequate support for the fuse. Thisburster charge will in the assembly of the structure be compressed uponthe fuse body and within the cavity, from the rear, and will be sufficiently dense to hold the fuse in place when the shell is fired from agun, that is, against set-back. The stress of set-back is relatively notgreat, particularly in the firin of large shell, and a fairly densecharge wi l easily hold the fuse in its forward position.

In United States Letters Patent No. 905,042, granted November 24, 1908,to A. \Vratzke, and in United States Letters Patent No. 1,105,849,granted me August 4, 1914, a certain advantage, incident to the use ofhigh explosives, of filling the anterior end of such a taperedburster-charge cavity with another body and forming that other body witha flat rear face, upon which the body of high explosive may be impacted,is dwelt upon: a tendency to spontaneous explosion under the strainsincident to service is met and overcome. That advantage is present inthe structure here shown and de scribed.

It is an advantage inherent in the structure here shown and describedthat the burster charge 4 is, on impact of the projectile upon heavyarmor, pressed close upon the body of the fuse. In the case of a basefuse, the strain of impact tends to separate the body of the burstercharge from the fuse.

The position which the fuse occupies is such that on impact of the shellthe fuse stays in place; there can be no driving forward of the fusebody, and no consequent hammer blow of fuse body upon another part, andno premature ignition of the shell charge by pinching of its substancebetween the fuse and the inner Wall of the shell.

The form of fuse shown in Fig. II is, as I have said, shown by way ofexample; the invention is not limited by the type of fuseemployed. Inthis instance-the fuse plunger 51, such as shown and described in UnitedStates Letters Patent No. 860,354, granted me as assignee of theinventor, Samuel D. Cushing, on July 16, 1907, arms centrifu gally, andon impact fires the percussion cap 52. The flash from the cap(augmented, as

presently will be explained) gains access rearwardly through the slot 53in which the firing pin swings, and through a passageway 54 formed inthe base block 55 of the fuse, to the delay train 56, consistingconveniently of a body of black powder lightly bore charged with thedelay train communicates. A booster charge 58 is conveniently carried inthe base block 55 and in such position relative to detonator 57 to bedetonated by it. This booster charge is further arranged in the verylowermost part of block 55, with only a thin web of metal separating it,when the parts are assembled as in Fig. 1, from the burster charge 4. Bysuch means the flash of the percussion cap, which occurs on impact, iswith preestablished delay effective to bring about detonation of thebooster charge and thereupon, of the burster charge of the shell,closely adjapent to which, as has been said, the booster The bore whichcarries the detonator is conveniently drilled through the upper oranterior face of base block 55, and, after loading, the detonator issecured in place by a felt washer 59 and then a plug 60 screwed into themouth of the bore.

The primer 52 is reenforced, and its flash intensified by means of asmall magazine charge 61 of black powder compressed sufliciently to givea long continued flash.

I claim as my invention:

1. An armor-piercing projectile Whose body is formed as an integralblock of metal tapered forwardly to a point and having within it aburster-charge cavity which extends from the rear forwardly part waytoward the point, a delay-action fuse arranged within and at theanterior end of the said burster charge cavity, a burster chargearranged with the cavity rearward of said fuse, and a base plug closingthe cavity to rearward.

2. An armor-piercing projectile whose body is formed as an integralblock of metal tapered forwardly to a point and having within it aburster-charge cavity which extends from the rear forwardly part waytoward the point and tapers forwardly, a delay-action fuse arrangedwithin and at the anterior end of said cavity and makingshape-sustaining abutment forwardly upon the cavity wall, a burstercharge arranged within the cavity to rearward of said fuse, and a baseplug closing the cavity to rearward.

3. In a projectile structure the combination of a shell providedinteriorly with a forwardly tapered cavity, a fuse having a forwardlytapered body complementary to the cavity in shape and arranged withinand at the forward end thereof and bearing forwardly with shapesustaining abutment upon the cavity wall, and a burster charge argangedwithin the cavity to rearward of said use.

4. In a projectile structure the combination of a shell providedinteriorly with a cavity closed forwardly and opening rearwardly, a fusearranged within such cavity and abutting upon the cavity wall at theforward end of the cavity, and a burster charge secured in the cavity torearward of said fuse and alone supporting said fuse in its aforesaidposition of abutment upon the wall of the cavity.

5. In a projectile structure the combination of a shell having within aburstercharge cavity closed at its forward end a fuse arranged withinand at the forward end of said cavity and abutting forwardly upon thecavity wall, and a burster charge arranged in the cavity to rearward ofsaid fuse and securing the fuse in its said position of abutment in thecavity wall,'the abutment so effected of the fuse forwardly upon thecavity wall being such as to exclude the intrusion between these partsof the substance of the burster charge.

In testimony whereof I have hereunto set my hand.

JOHN B. SEMPLE.

Witnesses:

J. CHESTER JUBIN, JOHN S. TODD.

